Knitting machine

ABSTRACT

A knitting machine having a cam system with a dividing cam to direct needle butts along one or other of two tracks, there being a butt edge on each needle for cooperation with a guiding cam in the cam system arranged to contact said butt edge and guide the needle along a chosen one of said tracks even when said needle butt is presented to the dividing cam so as partly to overlap said other track.

United States Patent Carrotte et a]. 1 Apr. 9, 1974 [5 KNITTING MACHINE 1,631,816 6/1927 Houseman 66/40 3,220,219 11/1965 Currier [75] lnven'tors: gi l? ,025,464 12/1935 Lombardi 66/50 East Gs t E l d FOREIGN PATENTS OR APPLICATIONS 578,070 9/1924 France 66/40 [73] Assgnee' i' fg g g 356,832 8/1922 Germany 66 40 [22] Filed: Feb. 9, 1972 Primary ExaminerRonald Feldbaum 21 Appl. No: 224,816

[57] ABSTRACT Foreign Application Priority Data A knitting machine having a cam system with a divid- Feb. 17, 1971 Great Britain ..4806/71 g cam to direct ed e bu ong one or other of two tracks, there being a butt edge on each needle for g." cooperation with a guiding cam in the cam system ar- [58] Fi i 66/50 123 57 24 ranged to contact said butt edge and guide the needle e 0 e c 66/42 6 along a chosen one of said tracks even'when said needle butt is presented to the dividing cam so as partly to l 5 6 1 References Cited overlap said other track.

UNITED STATES PATENTS 5 Claims, 7 Drawing Figures 2,038,895 4/1936 DiFonzo .1 66/123 1,767,595 6/1930 Lombardi 66/123 PATENTED APR .9 I974 SHEET 2 BF 2 KNITTING MACHINE This invention relates to knitting machines and is concerned with the problem of needle butt guidance in knitting machines in which needle butts are guided along one or other of two tracks by a dividing cam.

In such machines, the danger exists that a needle butt will present itself to the leading edge of the dividing cam so as to overlap the entrances to both of the trucks. In such a case, the butt will be broken off, making it necessary to stop the machine and replace the damaged needle.

The danger is significantly great in the case of circular knitting machines having uncrimped needles and yet in order to attain high knitting speeds in such machines it is desirable that the needles should be uncrimped to reduce generation of heat by friction between the needles and the trick walls and to reduce the forces resisting acceleration of the needles.

The present invention seeks to provide a cam and needle butt arrangement which reduces the risk of needle butt breakage by impingement of needle butts with the leading edge of a dividing cam. The invention is applicable to any knitting machine in which needles are operated by passage of butts through a cam system including a dividing cam.

A knitting machine according to the invention has a cam system including a dividing cam for guiding butts of needles along one or other of two tracks, and has needles each with a butt edge for cooperation with a guiding cam of the cam system arranged to guide the said needles so that a butt thereon will travel along a chosen one of the said tracks when the said butt is presented to the dividing cam so as partly to overlap the entry to the other of the said tracks.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which;

FIG. 1 is a perspective view of part of a cam system in a circular knitting machine, including a conventional dividing cam and also showing a needle of the machine,

FIG. 2 shows, on an enlarged scale, the region around the leading edge of the dividing cam in the cam system of FIG. I, and also shows a conventional needle butt,

FIG. 3 is a view' similar to that of FIG. 2 showing a dividing cam in a machine according to the invention and also showing a needle butt adapted for cooperation with this dividing cam,

FIG. 4 is a plan of the leading edge region of the dividing cam of FIG. 3,

FIG. 5 is a plan of the leading edge region of a conventional dividing cam and a dividing cam in a further machine according to the invention,

FIG. 6 is a view similar to that of FIG. 2 showing a dividing cam and needle butt in a still further knitting machine according to the invention, and

FIG. 7 is a view in the direction of the arrow A of FIG. 6 showing the dividing cam and a needle butt.

Like reference numerals are used for corresponding parts in all the Figures.

FIG. 1 shows part ofa conventional cam system, generally designated by the reference numeral 10, in a circular knitting machine having a rotatable needle cylinder. The cam system has a converging entry 11 which receives needle butts from the previous cam system (not shown) and an exit 12 which guides needle butts to the entry of the next cam system, generally designated by the numeral 13. The cam system 10 includes a dividing cam 14, a clearing cam 15 and a stitch cam 16.

A needle 17 of the knitting machine is shown at the right-hand side of FIG. 1. The needle has a camming butt 18 for cooperation with the tracks through the cam system 10. During operation of the knitting machine, the needles, which are mounted in tricks in the needle cylinder (not shown), are carried past successive cam systems and are operated by cooperation of their camming butts with the cams. The butt 18 of the needle 17, after travelling through the entry 11 of the cam system 10, must follow either a track 21 above the dividing cam 14 or a track 22 below the dividing cam. The track which the camming butt follows is determined by a known selector mechanism (not shown) which determines whether or not a jack (not shown) below the needle will engage its butt in a raising cam and thereby raise the needle so that the camming butt 18 follows a path such that it is in contact with the edge 23 and is presented to the entry 24 of the track 21 (FIG. 2). Needles 17 which are not raised in this way will have their camming butts 18 engage the edge 25 of the dividing cam 14 and these butts will be guided downwardly to follow the track 22.

The needles not raised by the selector mechanism do not normally follow a path which remains close to the edge 26 because when a camming butt 18 is freed from constraint against upward movement after leaving the entry 11, the upward force exerted on the needle 17 by the loop of yarn held on it pulls the needle and the butt upward. In some cases, the upward force and the resulting upward movement of the butt 18 are sufficient to raise the butt to the position 18 shown in FIG. 2. The butt 18 will then impinge on the leading edge 27 of the dividing cam 14 and will be broken off. The present invention is concerned with bringing about a reduction in the risk of this situation developing.

In the embodiment of the invention illustrated in FIGS. 3 and 4, the edge 25 of the dividing cam 14 is cut away to form a recess 28. The cam 14 thus has two cam surfaces 29 and 30, the surface 30 serving as a guiding cam surface located in front of the surface 29 with respect to the direction of movement of the needles, that is a needle carried forward by the rotation of the needle cylinder reaches the surface 30 before it reaches the surface 29. The camming butt 18 of each needle 17 is shaped, in this embodiment, as shown at the right-hand side of FIG. 3, so that a lower part 33 of the butt projects from the body of the needle by a conventional amount but an upper part 34 of the butt projects to a smaller extent, in fact by only half that amount. The butt thus has two edges 35 and 36 for cooperation with the cams of the machine.

The shape of the butt 18 in this embodiment and the size of the recess 28 are so chosen that the edge 36 on the butt projects only sufficiently far to cooperate with the surface 29 of the cam, but the edge 35 on the butt projects far enough to cooperate with the surface 30. Alternatively, it can be said that the guiding cam surface 30 projects only sufficiently far into the path of the needles to contact the butt edge 35. During normal operation of the machine, the edges 36 on the needle camming butts of raised needles engage the surface 29 of the dividing cam and the butts will be guided into the track 22. In addition, a needle butt presented to the dividing cam 14 in the position 18", partly overlapping the track 21, will have its butt edge 35 engage the cam surface 30 and will also be guided down into the track 22. In the conventional machine of FIGS. 1 and 2, a butt presented to the dividing cam in this way, partly overlapping the entry to the track 21, would be broken off. The edge 35 of the butt 18 of FIG. 3 thus serves to cooperate with the guiding cam constituted by the surface 30 in such a way as to guide needle butts into the track 22 even when the butts are presented to the dividing cam in such a way as partly to overlap the entry to the cam track 21.

In a further embodiment of the invention, the dividing cam of which is illustrated in FIG. 5, the dividing cam 14' is made thinner than a conventional dividing cam 14" which is also shown in this Figure for purposes of comparison. The cam 14 thus projects towards the needles of the knitting machine only to the same extent as the surface 30 of the dividing cam 14 of FIGS. 3 and 4. The cam 14 is thus able to cooperate only with the butt edge 35 of the butt 18 of the needle of FIG. 3.

In this case, the cam surface 37 (FIG. 5) constitutes both a dividing cam and a guiding cam for cooperation with the butt edges 35 on the needles to guide the needles into a track corresponding to the track 22 of FIG. 3 despite the fact that the needles are presented to the leading edge of the cam so as partly to overlap the other track which leads past the dividing cam.

However, in this embodiment, the dividing cam projects only sufficiently far into the path of the needles to contact the narrower part 33 of the butt 18 which is weaker than the wider part 34. An advantage of this embodiment is that it will allow the needle 17 to travel along the track 22 in a higher position than is the case when using a conventional dividing cam and camming butt.

The dividing cam 14 shown in FIGS. 6 and 7 has an additional upstanding portion 41, serving as a guiding cam, which is thinner than the main body of the cam and thus divides the track 21 above the dividing cam into a portion 21a which is only half the width of the corresponding track in a conventional machine of the same type and a portion 21b which is of conventional width. The dividing cam of FIGS. 6 and 7 is adapted for cooperation with a split-level camming butt 18 as shown at the right-hand side of FIG. 6. This butt has an upper portion 42 which projects to the same extent as a conventional camming butt and a lower portion 43 which projects to only half this extent. The butt-portion 42 has an edge 44 for cooperation with either the guiding cam portion 41 or with the main body of the dividing cam 14 and which serves to guide the needle 17 down and along the lower track 22 past the dividing cam. The butt edge 44 will guide a needle along the track 22 whenever the needle is presented to the dividing cam 14 in such a position that the butt edge 44 is below the leading edge 27 of the dividing cam, this leading edge being formed on the upstanding portion 41 of the cam.

Normally, the butt 18 will be presented to the dividing cam 14 in such a position that the whole of the edge 44 will be caused to cooperate with the main body of the cam 14, that is the edge 44 will come into contact with cam 14 below the broken line 45 in FIG. 7. Thus, in the majority of instances, the camming forces are borne by the part of the butt having the full conventional width. However, should theneedle be pulled up so that part of the butt 18 projects above the broken line 45, that is the butt partly overlaps the entry to the track 21, then, if the edge 44 of the butt is still below the leading edge 27 of the cam 14, the needle will still be guided down to the track 22.

Thus, as in the embodiments described above, the

embodiment of FIGS. 6 and 7 allows needles to ride up further than in a conventional knitting machine without fear of damage to the camming butts.

What is claimed is: r

1. In aknitting machine including needles, each having at least one needle butt having first and second substantially parallel opposite edges substantially perpendicular to the longitudinal axis of the needle, and a cam system including a dividing carn arranged for motion relative to each of said needles in a direction mutually perpendicular to the needle and the butt of said needle, said dividing cam having first and second cam surfaces diverging from a divergent edge in the direction of the movement of needles relative to said dividing cam for cooperation respectively with said first and second edges of each of said needle butts for guiding the needle butts along one or the other of two tracks depending on which of said edges of a needle butt contacts which of said carn surfaces, the improvement comprising an additional butt edge on each of said needle butts parallel to said first and second edges but at a level intermediate said first and second edges, said additional edge projecting longitudinally further from the needle than said first and second edges, and an additional cam surface on said dividing cam projecting in front of said first and second cam surfaces with respect to needle movement for contacting said additional butt edges to guide said needle butts into one of said tracks before said needle butts contact said first or second cam surface when said needle butts are presented to said dividing cam so that said first and second edges are on opposite sides of said divergent edge of the dividing cam.

2. A knitting machine according to claim 1 including a part on each of said needles projecting from the needle butt so as to extend further from the needle than said butt, said additional butt edge being provided on said part.

3. A knitting machine according to claim 2, wherein said additional cam surface is provided on a portion of said dividing cam projecting into the path of movement of the needle buttsto a smaller extent than the portion of said dividing cam including said first and second cam surfaces sufficient only to control said additional butt edges.

4. In a knitting machine having a cam system including at least one dividing cam arranged for motion relative to needles of said knitting machine in a direction perpendicular to the longitudinal axis of said needles, said dividing cam including dividing surfaces projecting a predetermined distance into the path of movement of butts on said needles for guiding the needle butts along one or the other of two tracks, the improvement comprising at least one further cam surface on said dividing cam, said further cam surface projecting farther than said predetermined distance into the path of movement of said needle butts, a butt projecting far enough from each needle to cooperate with said further cam surface but not far enough to contact said dividing surfaces, and a dividing butt attached to and extending from said needle, said dividing butt having a butt edge located farther from said needle than the end of said butt and sufficiently far from said needle to contact said dividing cam.

5. A knitting machine according to claim 4, wherein said dividing butt is attached to and extends from said butt.

$33 3? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,802,225 Dated April 9, 1974 Inventor) Frederick Henry Carrotte-John Ernest Ellis It is certified that "error appears in the above-identified patent and that said Letters Patent are hereby corrected -as shown below:

In the heading, item 75 should read: I

[75] Inventors: Frederick Henry Carrotte, of Kirby Muxloe;

and John Ernest Ellis, of East Goscote, England Signed and Sealed this 17th day of September 1974,

(SEAL) Attest:

McCOY M. GIBSON JR.- Q C. MARSHALL DANN Attesting Officer 3 Commissioner of Patents 

1. In a knitting machine including needles, each having at least one needle butt having first and second substantially paraLlel opposite edges substantially perpendicular to the longitudinal axis of the needle, and a cam system including a dividing cam arranged for motion relative to each of said needles in a direction mutually perpendicular to the needle and the butt of said needle, said dividing cam having first and second cam surfaces diverging from a divergent edge in the direction of the movement of needles relative to said dividing cam for cooperation respectively with said first and second edges of each of said needle butts for guiding the needle butts along one or the other of two tracks depending on which of said edges of a needle butt contacts which of said cam surfaces, the improvement comprising an additional butt edge on each of said needle butts parallel to said first and second edges but at a level intermediate said first and second edges, said additional edge projecting longitudinally further from the needle than said first and second edges, and an additional cam surface on said dividing cam projecting in front of said first and second cam surfaces with respect to needle movement for contacting said additional butt edges to guide said needle butts into one of said tracks before said needle butts contact said first or second cam surface when said needle butts are presented to said dividing cam so that said first and second edges are on opposite sides of said divergent edge of the dividing cam.
 2. A knitting machine according to claim 1 including a part on each of said needles projecting from the needle butt so as to extend further from the needle than said butt, said additional butt edge being provided on said part.
 3. A knitting machine according to claim 2, wherein said additional cam surface is provided on a portion of said dividing cam projecting into the path of movement of the needle butts to a smaller extent than the portion of said dividing cam including said first and second cam surfaces sufficient only to control said additional butt edges.
 4. In a knitting machine having a cam system including at least one dividing cam arranged for motion relative to needles of said knitting machine in a direction perpendicular to the longitudinal axis of said needles, said dividing cam including dividing surfaces projecting a predetermined distance into the path of movement of butts on said needles for guiding the needle butts along one or the other of two tracks, the improvement comprising at least one further cam surface on said dividing cam, said further cam surface projecting farther than said predetermined distance into the path of movement of said needle butts, a butt projecting far enough from each needle to cooperate with said further cam surface but not far enough to contact said dividing surfaces, and a dividing butt attached to and extending from said needle, said dividing butt having a butt edge located farther from said needle than the end of said butt and sufficiently far from said needle to contact said dividing cam.
 5. A knitting machine according to claim 4, wherein said dividing butt is attached to and extends from said butt. 